In keyboards, the trend is toward ever-flatter configurations. Thus, card readers integrated in keyboards should not interfere with the flat shape of the keyboard, as happens when a card reader is arranged vertically on the upper side of a keyboard. If, in addition, the function of a RFID card reader is to be integrated into the keyboard, then in the case of a keyboard with a vertically arranged card reader it is necessary to provide additional holding means for the card, such as a clip into which the card can be inserted. To overcome this drawback keyboards with horizontally arranged card readers have been developed. In these the card is introduced into a slot on one side of the keyboard, so the card can no longer be seen and can therefore easily be forgotten in the card reader, which is critical above all in the case of cards for authorization systems. Moreover, for a user it is not easy to see which way round the card is to be inserted into the slot. In existing contact-making units the contact block for the chip in the card is often positioned on the underside, so a user has to insert the card with its upper side facing downward, which is counterintuitive. Besides, the introduction of the card from the side into the card reader slot is ergonomically inconvenient, since the card must be held with two fingers and, particularly in the case of very flay keyboards, this can result in contact of the user's finger with the working surface. Extracting the card can often also be a problem, since the card projects only a very short way out of the card reader. Moreover, the insertion and extraction of the card require a sufficiently large free space on the side from which the card is to be inserted.